Hygroscopicity of butterfly-pea under room temperature: Effect on sorption and physicochemical properties

Abstract

This study aimed to determine the phenomenon during sorption on the whole dried and powder butterfly pea under room temperature storage. In addition, identified thermodynamics, hygroscopicity, degree of caking, and physicochemical properties to determine the quality of dried butterfly pea. Experiments applied the static gravimetric method by saturated salt at 13-27oC. The study results found that the best model was the Peleg Model. The increase in aw affects the increase in EMC during sorption. The comparison results indicated that the EMC of whole dried butterfly pea was smaller than that of powder. The net isosteric heat and differential entropy indicate a decrease with increasing EMC. However, spreading pressure indicates an increase with increasing aw. Dried butterfly pea has a hygroscopicity characteristic in the extremely hygroscopic category, and it was again identified that the degree of caking of butterfly-pea powder. Recommendations for drying and storage are carried out until the moisture content is 21.57% kg H2O/kg butterfly-pea solid (whole); 22.45% kg H2O/kg butterfly-pea solid (powder). The whole and powder butterfly-pea storage increased in L* and ΔE attributes and decreased antioxidant activity with increasing time and temperature.